1. Field of Invention
The invention relates to a stocking device and a process for stocking coilable elements such as cables, hosepipes, pipes, tubes, etc. in the stocking device. The invention further relates to stocking of all types of cables having a certain rigidity, i.e., capable of withstanding a certain axial compressive stress, without excessive buckling of the cables.
2. Description of Related Art
Installation of underground cables is quite complex due in part to the considerable lengths of the cables. This is particularly common with optical-type cables. In order to properly install these cables, a minimum number of cable splices is desired so as to maximize the quality of the signal carried through the cable. In order to accomplish the minimum amount of cable splices, a first portion of the cable is installed in a first tube heading in a given direction over several tens or hundreds of meters. A second portion of cable is then installed in a second tube, the opening of which is near the opening of the first tube. However, the second tube is usually oriented in a different direction from the first tube. By installing the two portions of the cable into the different tubes, a greater length without having to splice the cables is achieved.
However, in order to access the end of the cable which is in the opening of the second tube, the second portion must first be unwound from the cable roll. In order to uncoil the second portion of cable, it is necessary to carry out an intermediate stocking process which consists of uncoiling the cable on the ground and forming two juxtaposed circles. This method is often designated by the term "figure 8 technique". However, this technique presents numerous drawbacks including excess room and labor in order to, for example, (i) form the necessary circles and/or (ii) prevent the cable from becoming soiled. This method also presents risks for the wholeness of the cable and is slow and expensive to utilize.
The "Van Den Akker Reel" represents another method of coiling cables. In this method, the cable is not disposed on the ground. However, the Van Den Akker Reel includes successive stages of winding and unwinding which requires extensive time and labor. Moreover, it is still necessary to form Figure 8 loops over a portion of the length of the cable.
DE-C-22 02 177, FR-A-2015 977, EP-A 0 008 352 and EP-A-0 389 303 describe methods for winding and unwinding cables in a cylindrical stocking basket. These methods require a device for driving the cable and/or a device for rotating a laying arm. For example, the EP-A-0 389 303 device uses a stream of gas for rotating the laying arm. These methods also usually involve a device to synchronize between driving the cable and rotating the laying arm.
The American Document RE 34 488 describes a stocking device for winding a cable about a roll having a horizontal axis. This stocking device requires powerful drive means in order to carry out the winding. Also, the installation of this device requires numerous attachments for safety purposes, and in particular, for avoiding any contact with the rotating elements. This stocking device is very costly and complicated to use; compared with an installation comprising few or no rotary elements and/or driving devices.
As a further example, EP-B-0 296 860 describes a stocking device capable of being used as an intermediate stocking device having a stocking basket. This stocking device comprises a mechanical device that rotates a laying arm. This mechanical device has to be synchronized with a device that drives the cable. Also, in order to retrieve the lower end of the cable inserted on the bottom of the stocking basket, a number of manipulations to the basket, including an inversion operation must be performed. This stocking device can only be used with low-mass optical cables.